Subsea oil leak stabilization system and method

ABSTRACT

A method for controlling a subsea leak is provided using a manifold and an enclosing member extending above the manifold. The manifold includes a plurality of outlets directed toward a subsea bottom surface. The manifold and the enclosing member define an interior volume and are positioned so that the subsea leak is situated in the interior volume. The method includes jetting fluid out of the plurality of outlets of the manifold to remove subsea bottom material, and injecting fluidized concrete into the interior volume above the subsea bottom surface after the jetting fluid operation. The method also includes sealing the interior volume at a top of the enclosing member above the subsea leak. A device and system for controlling a subsea leak are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/396,937 filed Jun. 4, 2010, which is incorporated herein byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to subsea oil leaks, and in particularrelates to a subsea oil leak stabilization system (also referred toherein as SOLSS) and a method for developing and using a SOLSS.

2. Description of the Related Art

Water streams forced under pressure out a small diameter opening ornozzle (referred to herein as water-jetting or jetting) are used in theundersea construction industry and utilized for various tasks includingdredging, fishing, trenching, cable burial and pipe-line burial.Jet-assistance in a plowshare or other trenching tools can significantlyreduce the tow force (also referred to as draw-bar) required tosuccessfully pull plows through an array of various sub-bottom soils inundersea cable burial operations. Water-jetting is also used by underseaRemotely Operated Vehicles (ROV) and bottom crawlers to unbury andrebury cables and pipelines during repair operations.

Water-jetting may be relatively simple and involve native materials, forexample, the water source itself is readily available. Water jetting isan effective technique for fluidizing and cutting through bothunconsolidated and consolidated ocean bottom soils. The force requiredto pull plowing and burial tools through seabed soils depends on soildynamics and illustrates the effectiveness of seabed anchors.

The British Petroleum (BP) oil spill following the destruction of theDeepwater Horizon drilling platform in the Gulf of Mexico in 2010involved an oil leak from a wellhead on the sea bottom, also referred toherein as the sea floor or the subsea surface. The wellhead included anoil riser pipe and a blowout preventer. The BP oil spill was notcontained for several months causing significant environmental damageand imposing substantial monetary liabilities on BP.

BRIEF SUMMARY OF THE INVENTION

A method for controlling a subsea leak from an opening in a pipe whichextends from a subsea bottom surface is provided. The method uses anassembly including a manifold and an enclosing member extending abovethe manifold. The manifold includes a plurality of fluid outlets. Themanifold and the enclosing member at least partially define an interiorvolume, a bottom having an opening adapted to accommodate the pipe, anda top outlet. The method includes opening the top outlet to allow a freeflow of a fluid leaking from the pipe opening, and positioning themanifold to circumferentially enclose the pipe opening. The method alsoincludes jetting fluid out of the plurality of outlets of the manifoldtoward the subsea bottom surface to remove subsea bottom materialproximate the pipe after positioning the manifold, seat the bottom ofthe manifold into the subsea surface, and cause the manifold to movedownwardly relative to the pipe opening. The method further includesinjecting fluidized concrete into the interior volume above the subseabottom surface to a level below the pipe opening to seal the bottomopening, and closing the top outlet above the subsea leak to seal theassembly.

The method may include positioning the manifold to circumferentiallyenclose the subsea leak before the jetting fluid operation. The subsealeak may originate from a riser pipe, and the riser pipe may be avertical extension of a lateral pipe extending along the subsea bottomsurface. The manifold and the enclosing member may have aligned cut-outshaving a width greater than a diameter of the lateral pipe. Thepositioning of the manifold operation may include positioning thecut-out of the manifold over the lateral pipe. The method may include,before the injecting of the fluidized concrete into the interior volume,closing the aligned cut-outs of the manifold and the enclosing member

The method may include, after the jetting fluid operation, waiting toallow subsea bottom material to backfill around an exterior of theenclosing member before the injecting fluidized concrete operation. Themethod may include, after the jetting fluid operation, activelybackfilling subsea bottom material around an exterior of the enclosingmember before the injecting fluidized concrete operation.

The method may include, before the injecting fluidized concreteoperation, weighting at least one of the manifold and the enclosingmember to stabilize at least one of the manifold and the enclosingmember.

The method may include, before the sealing operation, closing a valveabove the subsea leak. The sealing operation may include capping theenclosing member above the valve.

The method may include, after the sealing operation, capping theenclosing member above a valve. The sealing operation may includeclosing the valve above the subsea leak.

The method may include, before the injecting fluidized concreteoperation, removing at least some of the subsea bottom material from theinterior of the enclosing member via outlets arranged on the enclosingmember.

A device for controlling a subsea leak is provided that includes amanifold having a plurality of outlets. The manifold is adapted to jetwater out of the plurality of outlets toward a subsea bottom surface tofluidize and displace subsea bottom material. The device also includesan enclosing member extending above the manifold and circumferentiallyenclosing the subsea leak. The enclosing member is adapted to receivefluidized concrete into an interior volume defined by the subsea bottomsurface after removal of subsea bottom material and the enclosingmember. The device further includes a seal at a top of the enclosingmember above the subsea leak.

The manifold may be positioned by a lift cable and/or one or moreremotely operated vehicles to circumferentially enclose the subsea leak.Aligned cut-outs of the manifold and the enclosing member may includeclosing doors.

The device may include stabilizing flanges arranged on an exterior ofthe enclosing member and adapted to stabilize the device in cooperationwith subsea bottom material that backfills around an exterior of theenclosing member.

The device may include weights arranged to removably attach to at leastone of the manifold and the enclosing member. The device may include avalve arranged in an interior of the enclosing member above the subsealeak and adapted to seal the enclosing member. The seal at a top of theenclosing member may be a cap situated above the valve.

The device may include a cap arranged on a top edge of the enclosingmember above the subsea leak and adapted to seal the enclosing member.The seal at a top of the enclosing member may be a valve arranged in aninterior of the enclosing member above the subsea leak.

The device may include outlets arranged on the enclosing member adaptedto remove at least some of the subsea bottom material from the interiorof the enclosing member before injecting fluidized concrete.

A system for controlling a subsea leak is provided that uses a manifoldand an enclosing member extending above the manifold. The manifoldincludes a plurality of outlets directed toward a subsea bottom surface.The manifold and the enclosing member may define an interior volume andmay be positioned so that the subsea leak is situated in the interiorvolume. The system includes means for jetting fluid out of the pluralityof outlets of the manifold to fluidize and remove subsea bottommaterial, and means for injecting fluidized concrete into the interiorvolume above the subsea bottom surface after the jetting fluidoperation. The system also includes means for capping the interiorvolume at a top of the enclosing member above the subsea leak.

The system may include means for actively backfilling subsea bottommaterial around an exterior of the enclosing member after jetting fluidand before injecting fluidized concrete, and means for weighting atleast one of the manifold and the enclosing member to stabilize at leastone of the manifold and the enclosing member before injecting fluidizedconcrete. The system may also include means for closing a valve abovethe subsea leak and below the top of the enclosing member beforecapping.

A method for controlling a subsea leak is provided using a manifold andan enclosing member extending above the manifold. The manifold includesa plurality of outlets directed toward a subsea bottom surface. Themanifold and the enclosing member define an interior volume and arepositioned so that the subsea leak is situated in the interior volume.The method includes jetting fluid out of the plurality of outlets of themanifold to fluidize and remove subsea bottom material, and injectingfluidized concrete into the interior volume above the subsea bottomsurface after the jetting fluid operation. The method also includessealing the interior volume at a top of the enclosing member above thesubsea leak.

A quick response Subsea Oil Leak Stabilization System (SOLSS) isprovided. The SOLSS approach defines a process for taking immediateemergency action for an oil leak, or other leaking pipe or riser. Thesystem uses naturally occurring components of the environment, includingwater and soil, to contain and seal a faulted oil riser pipe.

The SOLSS uses water-jetting and in situ seabed materials to provide astable permanent platform that has the potential for oil (or otherleaking material) containment, and possibly subsequent access to theleaking material in a controlled manner. A SOLSS may include a largestructure having modular components enabling assembly either dockside,onboard ship, or even underwater using standard construction techniquesand standard shipboard handling equipment. All equipment and resourcesused with a SOLSS may be commercial available and obtainable withminimal effort for quick response to an emergency situation similar tothe BP oil spill disaster.

The SOLSS uses a pipe, also referred to herein as a jetter pipe andalternatively any appropriate containing enclosure having an opening ona top and a bottom, and a pipe cap, also referred to herein as finalpipe cap, to create a pressure vessel. A manifold, also referred toherein as a jetter manifold, high volume water pumps and suctionequipment are also used, and may be the same or similar to these itemsas used in commercial equipment suites currently employed on cableplows, remotely operated vehicles, dredges and fishing trawlers. Amotorized gate valve is also used and may be similar to those used onocean bottom construction projects for the oil and gas industry.Fluidized concrete may be used and may be similar to the material usedin ocean bottom structures in offshore drilling and construction.

Once assembled and deployed, a SOLSS may quickly and efficiently stopthe flow of oil or other leaking material at the source, namely theriser pipe or other leaking pipe. The SOLSS may also create a stablebottom platform with a re-enterable final pipe cap enabling reopeningand resumption of oil recovery, thereby avoiding abandonment and loss ofthe initial drilling assets.

These objects and the details of the invention will be apparent from thefollowing description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of first exemplary embodiment of aSOLSS after deployment and activation;

FIG. 2A is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 at an initial deployment at a leak site;

FIG. 2B is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 after activation of the jetting manifold;

FIG. 2C is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 after introduction of stabilizing weights;

FIG. 2D is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 after injection of fluidizing concrete;

FIG. 2E is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 after closing a valve and installing a cap;

FIG. 3 is a cross-sectional plan view through the first exemplaryembodiment of the SOLSS shown in FIG. 1 at stabilizing flange 124;

FIG. 4A is a perspective view of a first stabilizing weight for use inan exemplary embodiment of a SOLSS;

FIG. 4B is a perspective view of a second stabilizing weight for use inan exemplary embodiment of a SOLSS;

FIG. 5 is a cut-away perspective view of a second exemplary embodimentof a SOLSS for use with lateral pipes after deployment and activation;and

FIG. 6 is a flow chart illustrating an exemplary method according to thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

SOLSS may include a large-diameter jetter pipe outfitted with twolarge-diameter flanges, one at its midsection, referred to as thestabilizer flange, and another near the bottom, referred to as theanchoring flange. The anchoring flange may form the upper portion of atriangular cross section and circular shaped water jet manifold withdownward facing jetter nozzles. The jetter pipe may also be outfittedwith a circular array of high volume water pumps mounted around itscircumference and above the stabilizer flange that feed a high volume ofwater to the water jet manifold. The jetter pipe assembly is alsooutfitted with a motorized gate valve for eventual shutdown of the oilflow. Additionally, the jetter pipe is outfitted with heavy lift-pointweldments, access ports for other subsea connections and an arrangementof pin openings at the very top for the eventual remote installation andlocking of a final cap.

Additional components of the SOLSS may include a set of reinforcedconcrete stabilization weights designed to fit over the jetter pipe tofurther stabilize the platform and resist the opposing force resultingfrom the oil exiting the riser pipe. The SOLSS is designed withmodularity to accommodate over-the-road transportation and/or easyassembly at dockside, onboard the work deck of a recovery vessel, and/orundersea at the site. Ancillary equipment may include heavy cranes, afluidized concrete provision, a composite umbilical/lift power cable, asoil suction (also referred to herein as a dredging) capability and oneor more heavy-duty, work-class Remotely Operated Vehicles (ROV). EachROV may be equipped with repair capability tools for marking, cutting,jetting and lifting/carrying some nominal payload.

FIG. 1 is a cross-sectional side view of first exemplary embodiment ofSOLSS 100 after deployment and activation. SOLSS 100 includes jetterpipe 130 having jetter manifold 110 coupled to a bottom edge of jetterpipe 130. Jetter pipe 130 in FIG. 1 is cylindrical, however alternativeshapes are possible and jetter pipe 130 is alternatively referred toherein as an enclosing surface or an enclosing member. Jetter pipe 130encloses riser pipe 102 that leaks oil 104. Jetter manifold 110 (alsoreferred to herein as a manifold) includes a plurality of jets 116arranged on externally directed surface 112 and internally directedsurface 113. Jetter manifold 110 includes chamber 114 which receives alarge volume of water from pumps 120 via feed lines 118. Pumps 120 maypump seawater or any other appropriate fluid. As the pressure in chamber114 rises due to the inflow of water, water flows out jets 116 at highpressure, causing the fluidization of subsea surface in the vicinity ofjets 116. Jets 116 may include mechanical or electronic controls,including valves, latches and/or solenoids, to provide individual orgroup control. In this manner jets 116 may be activated only onexternally directed surface 112 and not on internally directed surface113, or vice versa.

Jetter manifold 110 may form an inverted triangle in cross-section, withexternally directed surface 112 and internally directed surface 113forming the two lower sides, while anchor flange 128 forms the third andupper side. These three sides may define chamber 114. Anchor flange 128and internally directed surface 113 may join together at a point alongwith a lower edge of jetter pipe 130. Anchor flange 128 may be coupledto stabilizing flange 124 via flange support columns 126. Jetter pipe130 may include ports 132 on an exterior providing access to interior134 and which may be used for the suction or removal of material insidejetter pipe 130, for instance by flushing with seawater, also referredto herein as eduction. Additionally, ports 132 may be used for theinjection of fluidized concrete 180 into interior 134 of jetter pipe 130to form a plug and/or lower seal to jetter pipe 130 below a top edge ofriser pipe 102.

After SOLSS 100 has been activated to remove subsea material belowjetter manifold 110 through activation of jets 116 until stabilizingflange 124 is substantially even with the original subsea surface, oralternatively to a point that anchor flange 128 is considered to providea sufficiently stable anchor for SOLSS 100, stabilization weights 140may be positioned around jetter pipe 130 by lowering from above. Thepositioning of stabilization weights 140 may be accomplished usingrigging from surface ships, ROVs or a combination thereof. Eachstabilization weight 140 may include one or more weldments 142, whichmay be used for lifting and control. Stabilization weights 140 may beformed from reinforced concrete, and weldments 142 may include a loop ofreinforcing steel that exits and reenters the concrete of stabilizationweight 140. Stabilization weights 140 may include cut-outs to preventinterference with pumps 120, valve assembly 150, or any other element ofSOLSS 100 or its auxiliary or ancillary equipment (see FIGS. 4A and 4B).

Valve assembly 150 may operate to control valve 152. Valve assembly 150may be a motorized gate valve assembly. Valve 152, which may be a gatevalve, is shown in FIG. 1 as closed. Since valve 152 is closed in FIG.1, and since fluidized concrete 180 occupies the lower portion of jetterpipe 130 in SOLSS 100 below riser pipe 102, oil 104 is not able toescape SOLSS 100, and therefore there is no oil leakage shown in FIG. 1.

Cap 160, also referred to herein as a final cap, is positioned on a topedge of jetter pipe 130 and secured to jetter pipe 130 using cap pins164, which may be electrically, mechanically, or hydraulically operatedremotely and/or secured using one or more ROVs. Cap 160 may includereentry ports 162, which may be used for oil recovery at a later time,and/or for the installation or removal of material and/or instruments.Cap 160 may be positioned using lifting lines 172, which may becontrolled by a cap cable. The cap cable may in turn include anelectrical umbilical for controlling cap pins 164, for collecting videoor data, for subsea intervention and/or for any other appropriatepurpose.

SOLSS 100 may have a diameter or width 190, which may correspond to theouter diameter of jetter manifold 110. Width 190 may be approximately 30feet. Jetter pipe 130 and jetter manifold 110 may have a total height ofapproximately 50 feet, half of which may be buried beneath subsea bottommaterial after installation, and half of which may extend above thesubsea surface. For instance, distance 192 from the bottom of manifold100 to stabilizing flange 124 may be approximately 24 feet, and distance194 from the top of stabilizing flange 124 to the top of cap 160 may beapproximately 26 feet. Alternative sizes both larger and smaller may bepossible for different purposes.

FIG. 2A is a cross-sectional side view of SOLSS 100 shown in FIG. 1 atan initial deployment at a leak site. In FIG. 2A, SOLSS 100 is lowereduntil bottom edge 212 of jetter manifold 110 impacts subsea surface 210(also referred to herein as the seabed or sea floor) with loweringharness 220 attached to control points 222 on a top edge of jetter pipe130. Lowering harness 220 is held and controlled by control cable 224,which may or may not be the same as cap cable 170. SOLSS 100 ispositioned by control cable 224, with or without the assistance of oneor more ROVs, so that the bottom edge of manifold 110 surrounds riserpipe 102. Jetter pipe 130 includes one or more fluidized concrete lines200 connected at ports 132 on jetter pipe 130. Fluidized concrete line200 may be semi-rigid so that fluidized concrete line 200 extends awayfrom jetter pipe 130, and includes connection point 202, which may bebuoyant to prevent entanglement or burial of fluidized concrete line200. Valve 152 of valve assembly 150 is open in FIG. 2A allowing oil 104to escape into the sea, and also preventing the buildup of pressurewithin jetter pipe 130. Valve 152 may be controlled by valve assembly150, which may be motorized and controlled remotely. In this manner,SOLSS 100 may be positioned with maximum accuracy and stability.

FIG. 2B is a cross-sectional side view of SOLSS 100 shown in FIG. 2Aafter an initial deployment at a leak site. In FIG. 2B, jets ofinternally directed surface 114 and externally directed surface 112 ofjetter manifold 110 have been activated by pumps 120 to remove and orfluidize subsea bottom material beneath SOLSS 100, thereby loweringSOLSS 100 below subsea surface 210, and/or enabling SOLSS 100 to sinkinto subsea surface 210, for distance 192, or until stabilizing flange124 is even with subsea surface 210. During activation of jets viajetter manifold 110, control cable 224 may remain attached and tensionedto an upper portion of jetter pipe 130 to maintain SOLSS 100 in a stableposition and vertical orientation. Valve 152 is open in FIG. 2B,allowing oil to continue to escape into the sea. After an initialactivation of jets on both internally directed surface 114 andexternally directed surface 112 of jetter manifold 110 so thatstabilizing flange 124 is even with subsea surface 210, subsea bottommaterial 230 may be allowed to backfill an exterior area of SOLSS 100below stabilizing flange 124. This backfilling may stabilize SOLSS 100,and may additionally be assisted by ROVs using their onboard jetters toencourage backfilling of subsea bottom material 230.

During or after the backfilling of subsea bottom material 230 on theexterior of SOLSS 100, lower interior region 234 of SOLSS 100 may becleared or maintained clear of subsea bottom material 230 by activationof jets on internally directed surface 114 alone, without activatingjets on externally directed surface 112. Jets of jetter manifold 110 maybe independently controlled, either individually or in groups arrangedby region, size, or any other appropriate criteria. Control ofactivation of jets of jetter manifold 110 may be via a control link thatpasses via an umbilical within control cable 224, which may also controlother electrical functions, including power for pumps 120. Activation ofjets on internally directed surface 114 may fluidize any subsea bottommaterial 230 in lower interior region 234, which may be educted orevacuated via an evacuation hose connected to a port on jetter pipe 130.Alternatively, fluidized concrete line 200 including connection point202 may be additionally used to evacuate or educt subsea bottom materialfrom the interior of jetter pipe 130. Fluidized concrete line 200including connection point 202 may extend above subsea bottom surface210 due to the buoyancy of connection point 202. Interior 134 of jetterpipe 130 may be filled only or primarily with seawater following thebackfilling operation described above.

FIG. 2C is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 after introduction of stabilizing weights140. Stabilizing weights 140 may be positioned above stabilizing flange124 and may provide a downward force on SOLSS 100. The downward forceprovided by stabilizing weights 140 may be significant and may be gaugedto counteract any upward force expected to result from the closing ofvalve 152 and the consequent containment of oil 104 leaking from riserpipe 102. Additionally or alternatively, stabilizing weights 140 may beemployed during or before activation of jets of the jetter manifold topromote sinking of SOLSS 100 in resistant soils or for to increase thespeed of sinking and/or lowering of SOLSS 100. Stabilizing weights 140may include one or more control handles 142 for grasping by an ROV or asea surface shipboard control line or lines. Stabilizing weights 140 maybe generally toroidal, or donut-shaped, and may be continuous. In thecase of continuous stabilizing weights 140, stabilizing weights 140 maybe lowered from the sea surface already surrounding control cable 224.Alternatively in the case of continuous stabilizing weights 140, controlcable 224 may be disconnected for a period in which stabilizing weightsare installed on SOLSS 100. In still another alternative, stabilizingweights 140 may not be continuous and may include a thin cut-out sliceto allow insertion from the side in which control cable 224 may passthrough the slice to a central area of stabilizing weights 140.

FIG. 2D is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 after injection of fluidized concrete 180.After stabilizing the SOLSS using weights, and/or by maintaining tensionon the jetter pipe via control cable 224, an ROV may connect a fluidizedconcrete source on the sea surface to connection point 202. Connectionpoint 202 connects to fluidized concrete line 200, which accesses one ormore ports on the side of the jetter pipe below the subsea bottomsurface. Fluidized concrete is then injected into the jetter pipe toform fluidized concrete 180, which may extend from the bottom edge 182of the jetter manifold up to top surface 234 of fluidized concrete 180,which may be just below riser pipe top edge 236. In this manner, riserpipe 102 may be substantially encased in fluidized concrete, and asubstantial plug may be introduced on the bottom of the jetter pipe.

FIG. 2E is a cross-sectional side view of the first exemplary embodimentof the SOLSS shown in FIG. 1 after closing valve 152 and installing cap160. After fluidized concrete 180 has set, valve assembly 150 may becontrolled via electrical and/or optical umbilical 244 to close valve152. Closing valve 152 prevents oil from leaking into the sea from riserpipe 102. Pressure would subsequently increase in interior 134. Cap 160may then be installed on top of the jetter pipe using cap cable system170. Cap cable system 170 may include cap cable 240 and electricaland/or optical umbilical 244. Cap cable 240 may be coupled to liftinglines 172, which may operate to position cap 160 on the jetter pipe. Caplocking pins 164 may operate to lock cap 160 into position, and may beoperated remotely via electrical and/or optical umbilical 244, oralternatively may be secured using one or more ROVs.

FIG. 3 is a cross-sectional plan view through the first exemplaryembodiment of the SOLSS shown in FIG. 1 at stabilizing flange 124.Stabilizing flange 124 may be generally circular, and may include acentral opening. A border of the central opening 124 may represent across-section of jetter pipe 130, which may be circular. Interior 134 ofjetter pipe 130 may occupy the center point of the circle defined bystabilizing flange 124. Arranged around an exterior of jetter pipe 130and extending through stabilizing flange 124 may be feed lines 118 whichreceive high pressure and/or high volumes of water from pumps 120 whichmay be positioned above stabilizing flange 124. Each feed line 118 mayhave a corresponding pump 120, or alternatively multiple pumps 120, oralternatively two or more feed lines 118 may share one or more pumps120. The number and size of pumps 120 and feed lines 118 may be variedto vary the volumetric flow output of the jetter manifold according toparticular project requirements, including the size and weight of theSOLSS, and/or the soil characteristics.

FIG. 4A is a perspective view of first stabilizing weight 400 for use inan exemplary embodiment of a SOLSS. First stabilizing weight 400includes central cut-out 420, which may be circular and/or maycorrespond to the outline of the jetter pipe. Central cut-out 420 mayalso have one or more additional cut-outs 422 that correspond todifferent equipment on the exterior of the jetter pipe that may need tobe passed over during installation, for instance a motorized valveassembly. First stabilizing weight 400 may have first thickness 430,which may for example be approximately four feet. First stabilizingweight 400 may be positioned by moving first stabilizing weight 400along axis 410 around the jetter pipe.

FIG. 4B is a perspective view of second stabilizing weight 440 for usein an exemplary embodiment of a SOLSS. Second stabilizing weight 440includes central cut-out 450, which may be circular and/or maycorrespond to the outline of an array of pumps or water pumpssurrounding the jetter pipe. Central cut-out 450 may also have one ormore additional cut-outs 452 that correspond to different equipment onthe exterior of the jetter pipe that may need to be passed over duringinstallation, for instance a motorized valve assembly. Secondstabilizing weight 440 may have first thickness 460, which may forexample be approximately six feet. Second stabilizing weight 440 may bepositioned by moving second stabilizing weight 440 along axis 410 aroundthe jetter pipe.

FIG. 5 is a cut-away perspective view of a second exemplary embodimentof SOLSS 500 for use with lateral pipes after deployment and activation.SOLSS 500 may be used to seal leaks in a lateral pipe 510 that runslaterally along the subsea surface 210. Lateral pipe 510 may includeriser pipe 102 at an end where leaking is occurring, and which may beoriented vertically. In the event that riser pipe 102 of lateral pipe510 is not initially in a vertical orientation, ROVs or other mechanicalimplements may be utilized to create bend 515 in lateral pipe 510 toform a vertical section to make riser pipe 102. SOLSS 500 may includecut-out 520 having a width greater than a diameter of lateral pipe 510extending through elements from the bottom edge of jetter manifold 110up to anchor flange 128 and up to and including stabilizing flange 124.Cut-out 520 may be positioned to avoid contacting feed lines 118 andflange support columns 126. Cut-out 520 may terminate in cut-out top525.

During an initial deployment of SOLSS 500 on a leaking lateral pipe 510that includes riser pipe 102, which may be vertical initially orfabricated to be vertical, cut-out 520 may be aligned with lateral pipe510 on subsea surface 210. Jetting water via jetter manifold 110 mayremove subsea surface 210 lowering SOLSS 500 into subsea surface 210.Simultaneously, lateral pipe 510 may move relatively to SOLSS 500 upcut-out 520 until cut-out top 525 is reached. Subsequently, backfillingoperations and evacuating the interior of jetter pipe 130 may beperformed in the same manner as previously described. Likewise,fluidized concrete may be injected into the interior of jetter pipe 130to form a bottom seal of jetter pipe 130, and should be injected to afill point above cut-out top 525, and perhaps well above that point.Additionally or alternatively, cut-out 520 may be provided with a manualclosure system enabling cut-out 520 below the position of lateral pipe510 in a final position to be closed. Closure of cut-out 520 after ajetting operation of SOLSS 500 may be accomplished by motors, springs,latches, either remotely or by using an ROV assist, or by any otherappropriate method. Subsequent to the injecting of fluidized concreteinto the interior of jetter pipe 130 to a point above cut-out top 525and curing of the fluidized concrete, operations to complete closure ofthe jetter pipe 130 using a valve and/or cap may be performed in thesame manner as discussed above in regard to SOLSS 100.

FIG. 6 is a flow chart illustrating exemplary method 600 according tothe principles of operation of a SOLSS. The flow in FIG. 6 starts atStart 605 and flows to operation 610, which indicates to deploy thejetter pipe and establish/confirm correct position over site ofinterest. From operation 610, the method flows to decision 620, whichindicates to commence water jetting from plurality of outlets inmanifold to fluidize and remove subsea bottom material causing sinkageof jetter pipe into bottom. From operation 620, the method flows todecision 630, which indicates to allow subsea bottom material tobackfill beneath a stabilization flange around an exterior of theenclosing member. From operation 630, the method flows to operation 640,which indicates to weight at least one of the manifold and enclosingmember to stabilize at least one of the manifold and the enclosingmember. From operation 640, the method flows to operation 650, whichindicates to remove at least some of the subsea bottom material from theinterior of the enclosing member via suction outlets arranged on theenclosing member. From operation 650, the method flows to operation 660,which indicates to Inject fluidized concrete into the interior volume ofthe enclosing member above the subsea bottom surface after jetting fluidoperation. From operation 660, the method flows to operation 670, whichindicates to, after a short concrete cure, close a valve above thesubsea leak. From operation 670, the method flows to operation 680,which indicates to cap the enclosing member above the valve. Fromoperation 680, the method flows to End 690.

A more detailed explanation of exemplary method 600 follows. Dependingon water depth and potential bottom conditions, the leak site must beaccurately located, marked and engaged by whatever positioning andnavigational devices are available. Positioning accuracy should bewithin ±6 inches or less (if possible). Knowledge of bottom topographyand soil conditions and exact riser pipe specifications, condition andorientation would be helpful to assure proper locating, landing,intervention and an overall successful operation.

After proper location and position of the target have been determined, ajetter pipe (outfitted with large motorized gate valve and high volumewater pumps) may be deployed concentrically with the severed oil riserpipe directly over the leak site. Positioning and location technology incombination with each ROV may be useful to increase overall reliabilityof the operation. At this point, the large motorized gate valve is fullopen allowing oil flow to continue unrestricted vertically upward intothe sea. Note also that the fluidized concrete and suction lines canalso be deployed with the jetter pipe, or alternatively may besubsequently, remotely connected on the ocean floor using ROV assist.

After accurate deployment of the jetter pipe has been established, highvolume water pumps are turned on and commence water jetting and sinkageof the jetter pipe into the seabed until full depth (substantially 24feet in some exemplary embodiments) has been achieved. During thejetting operation (depending on sea conditions), some tension may needto be held on the lift line to control and maintain vertical attitude ofthe jetter pipe with respect to the seabed, and to maintain positionwith respect to the oil riser pipe. ROV support may be required duringwater jetting. Tensioning may also act to maintain and control sinkagerate into the bottom to prevent overturning of the jetter pipe andinadvertent damage to the oil riser pipe. If embedment is inadequate,the addition of stabilization weights early in the jetting process,prior to complete embedment, may enhance sinkage.

After water-jetting has been completed and proper attitude andpositioning of the jetter pipe with regard to the oil riser pipe havebeen established, the fluidized soil is allowed to settle, backfill andseal against the anchoring flange (connected to the jetter manifold).The settled soil, in combination with the anchoring flange, acts as astrong seabed anchor to resist pullout of the jetter pipe against theforce created by the oil-flow pressure after the motorized gate valvehas been closed. Approximately 24 hours of settling time may be requiredfor the fluidized soil to backfill. This process can be enhanced byapplying the jetter capabilities of an ROV to ensure that all or most ofthe excavated soil is completely backfilled. The backfilling may extendall the way up to the stabilizing flange. In the event that the jettingoperation is unable to embed the jetter pipe to the proper depth,mounding of backfill material around the jetter pipe up to or close tothe stabilizing flange at a point above the subsea surface may providesufficient anchoring of the jetter pipe.

After adequate settling has been established (which may be by observingan increase in lift-line tension against jetter pipe), deployment of“donut-shaped” stabilization weights directly over the jetter pipe maybe commenced. Cutouts in the stabilization weights may be aligned withexterior mounted equipment (fetter pumps and gate valve motors andhardware) to avoid the potential for damage to these elements. ROVs mayassist in verifying and assisting in this alignment.

It may also be advisable to suction, evacuate or educt fluidized soiltrapped inside the jetter pipe to prepare the jetter pipe for theintroduction of fluidized concrete.

After the jetter pipe has been stabilized and secured with ampledownward weight to resist expected forces caused by oil-flow pressure,fluidized concrete may be introduced from a host vessel at the watersurface. Fluidized concrete may be introduced into the cavity around oilriser pipe up to just below the top of its severed orifice to seal andprevent the lower portion of the jetter pipe. In this manner, the jetterpipe may be sealed against oil backflow and seepage, particularlythrough unconsolidated soils at the bottom of the jetter pipe. At thispoint, the motorized gate valve remains open to prevent any oil-floweffect on the proper setting of the fluidized concrete. Some tension onthe lift line may be maintained and the vertical attitude of jetter pipemay be monitored.

The concrete medium created by the fluidized concrete may seal the SOLSSfrom oil flow back pressure that could eventually cause oil to leak outaround the jetter manifold through coarse, non-cohesive soils aftercapping off and shutting down the jetter pipe later in the process.

After the concrete seal application has been verified, the motorizedgate valve may be closed down, at which point flow from oil riser pipeinto the ocean stops. After inspection and testing to verify that oilflow has been terminated, a final pipe cap may be deployed and installedover the jetter pipe, perhaps using ROV assist for the final remotelyoperated connection. After testing and inspection, the motorized gatevalve can be reopened if desired. The final pipe cap may be outfittedwith special ports to accommodate re-entry for future access to the oilsource, if desired. The final “leave behind” height of the SOLSSstructure may be less than 30 feet high and, at its largest point, about30 feet in diameter.

A weight estimate for each component using a nominal two-inch thicksteel for the pipe and flanges are as follows (FIGS. 1-5):

-   -   jetter pipe, flanges and jetter manifold 180 tons    -   reinforced concrete stabilization weights 360 tons    -   concrete seal 280 tons    -   final pipe cap 30 tons        -   Total System Weight 850 tons

The downward, normal force caused by the weight of the system may, incombination with the anchoring effect of the backfilled soil loadedagainst the anchoring flange, provide a stable bottom platform. Thefinal system requirements and the appropriate element sizes and weightsrequired to safely overcome the expected forces generated by the oilflow pressure may differ than those described above, which are merelyexemplary and not limiting. It is anticipated however, that a completedSOLSS could be the basis for start-up of a new oil producing platform orsimply sealed off with a possibility for future access.

It may be desirable that the faulted oil riser pipe have a verticalorientation with respect to the bottom. However, a fault in a lateralpipeline can be addressed with the same SOLSS configuration byintroducing an access slot, also referred to herein as a cut-out, on oneside of the system that is large enough to accommodate the lateral pipe(see FIG. 5). Once the lateral pipeline has been engaged properly, thecut-out may be closed manually and/or remotely, for instance by anelectrically operated latch releasing a spring to close one or twodoors, which may be hinged or sliding. After closure of any doors afterpositioning of the jetter pipe around the lateral pipe, the remainingprocedures may be substantially the same as described above.

The SOLSS is modular and may enable a second larger SOLSS to besubsequently deployed and erected around and over an initially deployedSOLSS. This feature may enable a different or updated device to be usedfor a new ocean surface oil rig. This reuse feature can be both costeffective and act to reduce overall environmental impact.

The SOLSS may be employed for a new offshore well, in combination withthe drilling operation, to provide at the onset a stable access riserwith all the necessary shutoff valves and safety features required toterminate oil flow immediately. This would mean that oil flow may beterminated almost immediately, at the main source, with a drasticallyreduced effect on the environment. The SOLSS, or elements thereof, mayalso be incorporated into a blowout preventer, and/or a blowoutpreventer may be incorporated into the SOLSS. Additionally, the SOLSSmay be used in conjunction with other wellhead systems.

Finally, while the SOLSS may be both stable and permanent with a hugeresistance to pullout, if removal of this structure is required for somereason, the outside portion of the jetter manifold, for example jets 116arranged on externally directed surface 112 could be activated tofluidize the soil immediately around the system to assist in itsdisassembly and recovery.

While only a limited number of preferred embodiments of the presentinvention have been disclosed for purposes of illustration, it isobvious that many modifications and variations could be made thereto. Itis intended to cover all of those modifications and variations whichfall within the scope of the present invention, as defined by thefollowing claims.

1. A method for controlling a subsea leak from an opening in a pipewhich extends from a subsea bottom surface using an assembly comprisinga manifold and an enclosing member extending above the manifold, themanifold comprising a plurality of fluid outlets, the manifold and theenclosing member at least partially defining an interior volume, abottom having an opening adapted to accommodate the pipe, and a topoutlet, the method comprising: opening the top outlet to allow a freeflow of a fluid leaking from the pipe opening; positioning the manifoldto circumferentially enclose the pipe opening; jetting fluid out of theplurality of outlets of the manifold toward the subsea bottom surface toremove subsea bottom material proximate the pipe after positioning themanifold, seat the bottom of the manifold into the subsea surface, andcause the manifold to move downwardly relative to the pipe opening;injecting fluidized concrete into the interior volume above the subseabottom surface to a level below the pipe opening to seal the bottomopening; and closing the top outlet above the subsea leak to seal theassembly.
 2. The method of claim 1, further comprising, after theinjecting of the fluidized concrete operation, waiting for the fluidizedconcrete to set prior to the closing of the top outlet operation.
 3. Themethod of claim 1, wherein: the subsea leak originates from a riserpipe, the riser pipe being a vertical extension of a lateral pipeextending along the subsea bottom surface; the manifold and theenclosing member have aligned cut-outs having a width greater than adiameter of the lateral pipe; and the positioning of the manifoldoperation further comprises positioning the cut-out of the manifold overthe lateral pipe.
 4. The method of claim 3, further comprising, beforethe injecting of the fluidized concrete into the interior volume,closing the aligned cut-outs of the manifold and the enclosing member 5.The method of claim 1, further comprising, after the jetting fluidoperation, waiting to allow subsea bottom material to backfill around anexterior of the enclosing member before the injecting fluidized concreteoperation.
 6. The method of claim 5, further comprising, after thejetting fluid operation, actively backfilling subsea bottom materialaround an exterior of the enclosing member before the injectingfluidized concrete operation.
 7. The method of claim 1, furthercomprising, before the injecting fluidized concrete operation, weightingat least one of the manifold and the enclosing member to stabilize atleast one of the manifold and the enclosing member.
 8. The method ofclaim 1, further comprising: before the closing operation, closing avalve above the subsea leak; wherein the closing operation comprisescapping the enclosing member above the valve.
 9. The method of claim 1,further comprising: after the closing operation, capping the enclosingmember above a valve; wherein the closing operation comprises closingthe valve above the subsea leak.
 10. The method of claim 1, furthercomprising, before the injecting fluidized concrete operation, removingat least some of the subsea bottom material from the interior of theenclosing member via outlets arranged on the enclosing member.
 11. Adevice for controlling a subsea leak, comprising: a manifold having aplurality of outlets, the manifold adapted to jet water out of theplurality of outlets toward a subsea bottom surface to displace subseabottom material to uncover a subsurface below the subsea bottom surfaceand lower the manifold; an enclosing member extending above the manifoldand circumferentially enclosing the subsea leak, the enclosing memberadapted to receive fluidized concrete into an interior volume defined bythe enclosing member and the subsurface after removal of the subseabottom material; and a valve arranged in the interior volume above thesubsea leak and adapted to open and allow fluid to flow through freelyand to close and seal the enclosing member.
 12. The device of claim 11,wherein the manifold is positioned by at least one of a lift cable and aremotely operated vehicle to circumferentially enclose the subsea leak.13. The device of claim 12, wherein: the subsea leak originates from ariser pipe, the riser pipe being a vertical extension of a lateral pipeextending along the subsea bottom surface; the manifold and theenclosing member have aligned cut-outs having a width greater than adiameter of the lateral pipe; the positioning of the manifold furthercomprises positioning the cut-out of the manifold over the lateral pipe;and the aligned cut-outs of the manifold and the enclosing memberinclude closing doors.
 14. The device of claim 11, further comprisingstabilizing flanges arranged on an exterior of the enclosing member andadapted to stabilize the device in cooperation with subsea bottommaterial that backfills around an exterior of the enclosing member. 15.The device of claim 11, further comprising weights arranged to removablyattach to at least one of the manifold and the enclosing member.
 16. Thedevice of claim 11, further comprising a cap situated above the valveand adapted to further seal the enclosing member, the cap includingremotely operated locking pins for securing the cap to the enclosingmember.
 17. The device of claim 11, further comprising outlets arrangedon the enclosing member adapted to remove at least some of the subseabottom material from the interior of the enclosing member beforeinjecting fluidized concrete.
 18. A system for controlling a subsea leakusing a manifold and an enclosing member extending above the manifold,the manifold comprising a plurality of outlets directed toward a subseabottom surface, the manifold and the enclosing member defining aninterior volume and being positioned so that the subsea leak is situatedin the interior volume, the system comprising: means for jetting fluidout of the plurality of outlets of the manifold to remove subsea bottommaterial; means for injecting fluidized concrete into the interiorvolume above the subsea bottom surface after the jetting fluidoperation; and means for capping the interior volume at a top of theenclosing member above the subsea leak.
 19. The system of claim 18,further comprising: means for actively backfilling subsea bottommaterial around an exterior of the enclosing member after jetting fluidand before injecting fluidized concrete; means for weighting at leastone of the manifold and the enclosing member to stabilize at least oneof the manifold and the enclosing member before injecting fluidizedconcrete; means for closing a valve above the subsea leak and below thetop of the enclosing member before capping.
 20. A method for controllinga subsea leak comprising: jetting fluid out of a plurality of outlets ofa manifold circumferentially surrounding the subsea leak, the pluralityof outlets being directed toward the subsea bottom surface to removesubsea bottom material; injecting fluidized concrete into an interiorvolume defined by the manifold and an enclosing member extending abovethe manifold; and sealing a top outlet of the interior volume, the topoutlet being above the subsea leak.